Elixir / Phoenix containerized development environment

What you get

• One-line dev environment setup: docker-compose up. It creates the database, does the Dialyzer pre-work (if the project has Dialyxer installed), and everything else.
• Development-oriented config: Source code is mounted so that changes in the container appear on the host, and vice-versa.
• Fast re-builds because the DOCKERFILE is written to help Docker cache the images.
• Syncing with Postgres startup delay.
• All the crappy little dependencies installed.
• No weird hacks.

Uses Elixir 1.6.1, Phoenix 1.3.0, and latest Postgres. These are the latest versions as of 2018-02-02. Tested on MacOS and Fedora Linux, because that's what I happen to use. This is my configuration I develop with.

Instructions

1. Copy the three config files to an existing Phoenix project which you want to Dockerize. Make run.sh executable, e.g. chmod +x run.sh.
2. Edit your development database settings to connect to Postgres at host db, username postgres, password empty string.
3. Spin it up with docker-compose up.

Tests can be run in the container like so:

docker-compose run web mix test

Or, for a slightly faster startup time,

docker-compose exec web mix test

... I haven't found a disadvantage of re-using the running container this way.